[Purpose] To evaluate the effects of early passive range of motion exercise on the function of upper extremities and activities of daily living in patients with acute stroke. [Methods] A total of 37 patients with acute stroke in intensive care units, were assigned to the experimental group (n=19) and control group (n=18). The experimental group performed passive range of motion exercise twice a day, for 4 weeks, immediately after a pretest; the patients in the control group performed the range of motion exercise in the same manner for 2 weeks beginning 2 weeks after the pretest. The functions of upper extremities (edema, range of motion), manual function, and activities of daily living of both groups were measured before and at four weeks after the intervention. [Results] The experimental group showed a significant decrease in the edema of upper extremities compared with the control group. It also showed a significant increase in the range of motion, function of upper extremities, and the activities of daily living compared to the control group. [Conclusion] Passive range of motion exercise in the early stage can improve the function of upper extremities and activities of daily living in patients with acute stroke.